Single wire arc tube support



' Aug. 13, 1957 JENNE, JR 2,802,961

SINGLE WIRE ARC TUBE SUPPORT Filed Sept. 16. 1954' Fi z.

In ven tor' Frank define, J11,

His A ls tovheg.

2,802,961 snsGrtE WIRE ARC TUBE SUPPORT Frank J enne, Jr., Euclid, Ohio, assignor to General Electric Company, a corporation of New York Appliu'ation september 16, 1954-,Serial No-.-456-,374

4' Claims. (Cl. 31'325) The present invention relates'to high-pressure electric discharge lamps having an inner are tube of vitreous materia'l, an outervitre'ous envelope and a mount structure supporting said tube in said envelope.

The principal object of the present invention is to simplify the manufacture and thus reduce the cost of such lamps by providing an arc tube mount which'eliminates the separate arc tube support members used heretofore. Further objects and advantages will appear from the following detailed description of a species of the invention, from the accompanying drawing and the appended claims.

A feature of the invention is an arc tube mount inclil'ding' a harness constituted by a single piece of metal wire suitably bent and shaped to engage directly around the arc' tube seals and serving also the same purpose as the U-shaped harness used heretofore in conjunction with separate arc tube support members. A further feature of the. harness of the present invention is the provision of integral square-shaped collars for receiving arc tube seals ofeithe'r the fiat press type or the cylindrical type.

In the drawin accompanying and forming part ofv this specification an embodiment of the invention is shown inwhic'h:

Fig. 1 is a front elevational view of a discharge lamp of the high-pressure type in which the-mount for the are tube within the outer envelope of the lamp includes a harness' constituted by a single piece of metal wire in acco'rdance with the present invention;

Fig; 2 is a perspective view of the harness on an enlarged scale;

Fig. 3 is a top plan sectional view along the line 33 ofFig. l and taken in the direction of the arrows; and

Fig. 4 is a similar view showing a flat press type of seal engaged by the new harness.

Like members denote like-parts in all the figures.

Referring to Figs. 1 to 3 of the drawing, the lamp illustrated is of a well-known commercial type except for the arc tube supporting harness described in detail hereinafter and, therefore, a brief description of the lamp will suffice for the purpose of providing a complete understanding of the invention. The lamp shown is known commercially as the H400E1 lamp.

The lamp comprises an outer vitreous light transmitting envelope 1 having a re-entrant stem 2 through the pinched or pressed part 3 of which extends two leading-in wires 4 and 5 which are connected at their outer ends to the contacts of the usual screw type base 6 of the lamp and which terminate within the outer envelope 1 for connection to the terminals of the inner arc tube 7. The inner arc tube is made of hard vitreous light transmitting material, such as quartz, and has sealed therein at opposite ends thereof a pair of main discharge supporting electrodes 8 and 9 of tungsten and material of high electron emissivity, such as alkaline-earth oxide, thorium and mixtures thereof. The inleads 10 and 11 of the electrodes 8 and 9 constitute the terminals of the arc tube 7.

An auxiliary starting electrode 12 is sealed into one end of the arc tube 7 adjacent the main electrode 9. The

nited States Patent 0 F Patented Aug. 13, 1957 ri 1C6 current"'inleads"'10,l11' and 13 for" the said electrodes 8, 91and 12; respectively, have a molybdenum foil'ribbon hermetically united by fusion directly with the quartz of the cylindrical quartz tube seals 14 and 15 extending outwardly from the arc tube 7.

In the 4'00-watt'size, the arc tube 7 has a filling'of'starting gas, such as argon; at a pressure of about 2.5 centi meters at room" temperature and a measured quantity of mercury'sufiicient to produce a high-pressure, unsaturated vapor'atmosphere at the operating temperature of the arc tube; Theou-ter' envelope 1 is filled with nitrogen at about half-atmospherepressure; During operation of the lamp, the main arc discharge between the'electrodes 8 1 and 9 is constricted by the high-pressure vaporatmos= phere and' has the appearance of a luminous chordspaced from the inner surface of the arc tube 7.

The outer envelope 1 has tubular'portions'16 and 17 at its ends and" a spherical portionlfi at its center.

' The-most for the arc tube 7 within the outer envelope l comprises a harness 20" consisting of a single piece'of metal-wire of 'nick'el -iron alloy, for example, suitably bent to-form parallel parts 21 and 22 extending longitudinally of the are tubemountingspace and corresponding to the parallel legs of the usual U-shaped support. The harness-20 has also laterally extendingarc tube seal engaging p'a'rt'scorresponding to the individual arc tube supports used heretofore and providing square-shaped collars '23 and 24 for receiving and engaging the externally protruding seals 14 and 15 at the ends of the arc tube 7'.

The square-shaped collars 23- and- 24 are each constituted by two integral, suitably bent, complementary opp'os'ed portions of" the'single wire harness 20'. The said wire harness portions extend generally transversely of the arc tube nrountingspaceand the two bent wire portions constituting collar 23 have aligned straight ends 25- and 26, 27 and 28, respectively. The two bent wire portions constituting collar 24 have similarly aligned straight ends- 29" and 30', 31- and 32, respectively. The square-shaped collars-2'3 and 24 are formed by the afore said complementary opposed wire portions which have right-angle bends therein constituting the corners 33 and 34; 35 and 36' of the collars 23 and 24, respectively.

The part of the wire harness 20 at the stem end of the mount is U shaped' and has twoparallel legs 37 and 38 and a bight 39 which, during assembly of the mount, is attached, as by welding, to'the current inlead 4 extending through the press" 3' of the said tube of the outer envelope 1 of the lamp (Fig. 1 The end portions of" the single Wire making up the harness 20 are bent to form a rec'- tangle having parallel sides 40 and 41 to which the spring braces 42 and 43 (Figs. 1 and 3') are attached as by Welding after the ends 44' and 45 of the aforesaid wire are welded together-as shown at 46 (Fig. 1) during assembly of the harness and the arc tube. The upper transverse portion 47 of the wire holds the parts 40 and 41 thereof in spaced position after the ends 44 and 45 have been welded as shown at 46 (Fig. 1).

In assembling the lamp, the cylindrically shaped seals 14 and 15'- at opposite ends of the arc tube 7 are positioned within the square-shaped collars 23 and 24 of the shaped harness 20 before the ends 44 and 45 of the wire making up the harness are attached to each other. The parts 25 and 27, 2b and 28, 29' and 3-1, 30 and 32 of the harness 20 are then permanently fastened to each other, respectively, preferably by welding, to hold the arc tube 7 in the harness 20. The ends 44 and 45 of the wire making up the harness are then welded together at 46, as shown in Fig. l.

The other elements of the mount are then secured together, preferably in the following manner.

The spring braces 42 and 43 and the heat shielding metal disk 48, the latter being slit to fit between legs 37 and 38, are welded to the harness 20 as shown. The assembly of the harness 20 and the arc tube 7 is then fastened to the stem 2 of the outer envelope 1 by welding the bight 39 of the harness 20 to the inner end of the current inlead 4 fusion sealed through the press 3 of the stem. The electrical connections between the current inleads 4 and 5 and the electrodes 8, 9 and 12 of the arc tube are then made as follows:

Flexible metal Wire current lead 49 is welded to inlead 5 and to the terminal 11 connected to electrode 9. Starting electrode 12 is connected to the harness 20 through the flexible inlead 50 and the usual resistance 51, one end of which is welded to the harness 20 as shown in Fig. The flexible inleads 49 and 50 extend through a central opening in the disk 43 and are insulated therefrom and from each other by surrounding glass tubes 52 and 53, respectively. The main electrode 8 is connected to the current inlead 4 at the stem end of the lamp through the terminal and the flexible current lead 54 welded to the part 41 of the harness.

The complete mount including the stem 2 with the arc tube 7 engaged by the harness 20 is inserted through the neck 17 of the outer envelope 1. The other steps in the manufacture of the lamp, including the fusion seal ing of the stem 2 to the neck 17 of the outerenvelope and the exhausting of air from envelope 1 and filling with nitrogen are then carried out in the usual manner.

It will be noted that the parts 21 and 22 of the harness 20 disposed in diametrically opposite positions with respect to the arc tube 7 are more widely spaced apart than the parts 37 and 38, 40 and 41 of the harness. The wider spacing of these parts 21 and 22 have been found advantageous for minimizing shadows cast thereby during operation of the lamp.

The square-shaped collars 23 and 24 of the harness each have a diagonal connecting the corners 33 and 34, 35 and 36, respectively, which is normal to the transversely extending parts 25 to 28, 29 to 32 0f the harness. Of course, the other diagonal of each of said squareshaped collars 23 and 24 is parallel to said transverse portions. When used with cylindrical seals of the type shown at 14 and of Fig. 1, the sides of the square-shaped collars engage around the said seals. The transverse parts of the harness are so spaced with respect to each other that the collars 23 and 24 engage the parts of the arc tube 7 flaring outwardly from the inner ends of said seals 14 and 15. The are tube 7 thus is held in proper position in said harness and thereby in said outer envelope 1. When used with flat press seals, such as the seal 56 shown end-on in Fig. 4, the side edges of the said fiat seals are engaged by the corners 33 and 34, 35 and 36, respectively, of the collars 23 and 24 of the harness 20. The spacing of the collars 23 and 24 is such that the arc tube equipped with such flat press seals is engaged by said collars as described above. Thus, the harness 20 is capable of universal use with arc tubes equipped with either cylindricalshaped seals or seals of the flat press type.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A high-pressure electric discharge lamp comprising in combination, an outer vitreous envelope, an inner vitreous arc tube having externally extending seals at its ends, and a mount supporting said tube within said envelope, said mount comprising a harness consisting of a single bent wire having spaced parallel parts extending longitudinally of and being oppositely disposed with i respect to said are tube and spaced parallel parts extending transversely of and engaging said are tube, each of the said transversely extending parts having complementary opposed bent portions providing a square-shaped collar, said collars engaging the seals at the ends of the arc tube.

2. A metal single wire universal support for vitreous arc tubes having externally extending cylindrical or flat press type seals at the ends thereof, said support being in the form of a harness having spaced parallel parts extending longitudinally of and being oppositely disposed with respect to the arc tube mounting space and spaced parallel parts extending transversely of the said mounting space, each of said transversely extending parts have complementary opposed bent portions providing a squareshaped collar normal to said mounting space for engaging a seal of an arc tube in said mounting space.

3. A metal single wire universal support for vitreous arc tubes having externally extending cylindrical or flat press type seals at the ends thereof, said support being in the form of a harness having spaced parallel parts extending longitudinally of and being oppositely disposed with respect to the arc tube mounting space and spaced parallel parts extending transversely of the said mounting space, each of said transversely extending parts have complementary opposed bent portions providing a squareshaped collar normal to said mounting space for engag ing a seal of an arc tube in said mounting space, one end of said harness being U-shaped and the opposite end thereof being rectangular, the distance between the longitudinally extending parts of said harness opposite said mounting space being greater than the distance between the longitudinally extending parts at the ends of said harness to minimize the shadows cast by said harness during operation of a supported arc tube.

4. An assembly for insertion within an outer vitreous envelope having tubular ends, said assembly comprising an arc tube having externally extending seals at the ends thereof, a vitreous stem for said envelope having current inlead wires fused to and extending through the press part of said stem, a metal single Wire supporting harness engaging said are tube seals and attached to one of said current inlead wires, said harness having spaced parallel parts extending longitudinally of and being oppositely disposed with respect to said are tube and having also spaced parallel parts extending transversely of said are tube and into engagement with said seals at the ends thereof, each of said transversely extending parts having complementary opposed bent portions providing a square-shaped collar, said collars engaging the seals at the ends of said arc tube, one end of said harness being U-shaped and the bight of said U-shaped end being attached to an inlead Wire of said stem, the opposite end of said harness being rectangular, the distance between the longitudinally extending parts of said harness oppo site said arc tube being greater than the distance between the longitudinally extending parts at the ends of said harness to minimize the shadows cast by said harness during operation of the supported arc tube.

References Cited in the file of this patent UNITED STATES PATENTS 2,042,148 Gaides et al May 26, 1936 2,104,652 Inman Jan. 4, 1938 2,142,047 Cox Dec. 27, '1938 2,177,712 Jenkins et a1 Oct. 31, 1939 

